Avaliação de cultivares de milho em função de populações de plantas e épocas de semeadura
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Data
2013-04-16
Autores
Pinotti, Elvio Brasil [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As constantes modificações de ordem morfofisiológica que tem ocorrido nas cultivares de milho obrigam a uma permanente reavaliação de posicionamento quanto aos aspectos fitotécnicos associados, principalmente a época de semeadura e distribuição espacial das plantas de milho. A hipótese de que cultivares com exigência de somatório térmico distintos respondem de maneira diversa em suas características morfológicas e fisiológicas quando semeados em épocas, com conseqüência sobre a produtividade foi considerado no presente trabalho. Portanto o objetivo deste trabalho foi de verificar alterações morfologias e fisiológicas de dois cultivares de milho, com somatórias térmicas distintas, semeadas em quatro populações de plantas, 30.000, 45.000, 60.000 e 75.000 pl ha-1 e três épocas de semeadura, janeiro, fevereiro e março, dentro do período da safrinha. O experimento foi conduzido em área de Argissolo Vermelho Amarelo Distrófico, arênico, situado na Fazenda do Engenho, no município de Pompeia (SP), na época da safrinha de 2010. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 2 x 4 x 3, com quatro repetições, em parcelas de sete linhas espaçadas de 0,45m, com 12m de comprimento. Foram avaliadas as características morfológicas e agronômicas estandes inicial e final, altura de plantas, número de folhas, altura de inserção de espiga, relação entre altura de espiga e altura de planta, diâmetro de colmo, área foliar por planta, índice de área foliar, índice de persistência e senescência foliar, grau Brix no florescimento masculino e maturidade fisiológica, porcentagem de plantas acamadas e quebradas. Foram também avaliadas as características de espiga e os componentes de produção, comprimento da espiga, número de fileiras de grãos por espiga, diâmetros da espiga e...
The constant morphophysiological changes that have occured in maize cultivars requires na ongoing reassessment of the issues associated to crop management specially seeding time and spatial distribution of maize plants. The hypothesis that cultivars with different thermal requirements respond in different times, with consequences to their productivity was considered in this work. Therefore the objective of this essay was to verify morfhological and physiological changes of two maize cultivars with different thermal sums, seeded in four different plant populations, 30,000; 45,000; 60,000 and 75,000 pl ha-1 and three seeding dates, january, february and march, within the period of the second crop. The experiment was conducted in na area located at Farm of Engenho in Pompeia – SP, Brazil, during the second crop season of 2010. The experimental design was a randomized block design in a factorial scheme of 2 X 4 X 3 with four replications in plots of seven rows spaced 0,45m and 12 m long. It was evaluated the morphological and agronomic characteristics and initial and final plant populations, plant height, number of leaves, height of insertion of ear, relationship between ear insertion height and plant height, stem diameter, leaf área per plant, leaf área índex, persistence índex and leaf senescence, Brix rate at male flowering and physiological maturity, percentage of plants broken and stalk loged plants. As well the evaluated the characteristics of ear and yield components, eat length, number of kernel rows per ear, ear diameter and cob, grain length, weight of thousand grains, grain weight per ear, number of grains per ear, number of ears per hectare, ear index and productivity. The parameters evaluated were influenced by hibrids, except leaf area in male flowering, leaf area at physiological maturity, grain length, thousand grain weight... (Complete abstract click electronic access below)
The constant morphophysiological changes that have occured in maize cultivars requires na ongoing reassessment of the issues associated to crop management specially seeding time and spatial distribution of maize plants. The hypothesis that cultivars with different thermal requirements respond in different times, with consequences to their productivity was considered in this work. Therefore the objective of this essay was to verify morfhological and physiological changes of two maize cultivars with different thermal sums, seeded in four different plant populations, 30,000; 45,000; 60,000 and 75,000 pl ha-1 and three seeding dates, january, february and march, within the period of the second crop. The experiment was conducted in na area located at Farm of Engenho in Pompeia – SP, Brazil, during the second crop season of 2010. The experimental design was a randomized block design in a factorial scheme of 2 X 4 X 3 with four replications in plots of seven rows spaced 0,45m and 12 m long. It was evaluated the morphological and agronomic characteristics and initial and final plant populations, plant height, number of leaves, height of insertion of ear, relationship between ear insertion height and plant height, stem diameter, leaf área per plant, leaf área índex, persistence índex and leaf senescence, Brix rate at male flowering and physiological maturity, percentage of plants broken and stalk loged plants. As well the evaluated the characteristics of ear and yield components, eat length, number of kernel rows per ear, ear diameter and cob, grain length, weight of thousand grains, grain weight per ear, number of grains per ear, number of ears per hectare, ear index and productivity. The parameters evaluated were influenced by hibrids, except leaf area in male flowering, leaf area at physiological maturity, grain length, thousand grain weight... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Milho safrinha, Milho safrinha – Semente, Produtividade agrícola, Semeadura, Milho - Fisiologia, Corn - Physiology
Como citar
PINOTTI, Elvio Brasil. Avaliação de cultivares de milho em função de populações de plantas e épocas de semeadura. 2013. xi, 121 f. Tese (doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agronômicas de Botucatu, 2013.